So, I gues I just got it by haunted hardware myself.
I have a Lenovo L560 for work. Its in the Lenovo Pro Dock.
For the past few days, every few hours to every hour both my external monitors will tell me, that they aren't getting a signal anymore and turn off.
Then I have to unlock the dock, unhook the laptop and put it back into the dock.
So I went to the helpdesk and the technician told me that he had a similar case a few days earlier.
He said, that the solution to that problem was that the other colleague used to put his phone on the laptop when not in use and that that was the source of problems.
I thought that that was very weird and he also couldn't tell me how that would work but I started not putting my phone on the laptop aswell and the monitors stopped turning off.
Then I acidentally put my phone on the laptop after using it and both screens went black.
I tried to recreate it with my phone a few times and it broke the signal most times.
To be sure, I tried putting a stapler and other similarly heavy stuff onto the laptop, as to be sure that is wasn't just a loose connection, but none worked.
Does anyone have an idea why this could be?